Currently

If I rely on the config's default of Include files (**/*) with the following Maven report dirs:

+- .../target/site
   +- css
   |  +- *.css
   +- images
   |  +- *.gif
   |  +- *.png
   +- *.html

The HTML Publisher's main page looks like:

i.e. it includes all files to view though *.css and images are just associated with *.html, of course, and should not be considered there.

Future option in the config

Files included but not published